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Related papers: Gate-tunable bandgap in bilayer graphene

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Bilayer graphene -- two coupled single graphene layers stacked as in graphite -- provides the only known semiconductor with a gap that can be tuned externally through electric field effect. Here we use a tight binding approach to study how…

Mesoscale and Nanoscale Physics · Physics 2010-04-29 Eduardo V. Castro , N. M. R. Peres , J. M. B. Lopes dos Santos , F. Guinea , A. H. Castro Neto

We evaluate the electronic transmission and conductance in bilayer graphene through a finite number of potential barriers. Further, we evaluate the dispersion relation in a bilayer graphene superlattice with a periodic potential applied to…

Mesoscale and Nanoscale Physics · Physics 2011-01-21 M. Barbier , P. Vasilopoulos , F. M. Peeters , J. Milton Pereira

Over the years, great efforts have been devoted in introducing a sizable and tunable band gap in graphene for its potential application in next-generation electronic devices. The primary challenge in modulating this gap has been the absence…

At large commensurate angles, twisted bilayer graphene which holds even parity under sublattice exchange exhibits a tiny gap. Here, we point out a way to tune this tiny gap into a large gap. We start from comprehensive understanding of the…

Mesoscale and Nanoscale Physics · Physics 2024-03-22 Xiu-Cai Jiang , Yi-Yuan Zhao , Yu-Zhong Zhang

We report on infrared spectroscopy of bilayer graphene integrated in gated structures. We observed a significant asymmetry in the optical conductivity upon electrostatic doping of electrons and holes. We show that this finding arises from a…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Z. Q. Li , E. A. Henriksen , Z. Jiang , Z. Hao , M. C. Martin , P. Kim , H. L. Stormer , D. N. Basov

Bilayer graphene (BLG) possesses a finite bandgap when a potential difference is introduced between the two graphene layers. The potential difference is known to be introduced by surface charge transfer. Thus, it is expected that a finite…

Materials Science · Physics 2014-12-04 Ryo Nouchi

In gapped bilayer graphene, similarly to conventional semiconductors, Coulomb impurities (such as nitrogen donors) may determine the activation energy of its conductivity and provide low temperature hopping conductivity. However, in spite…

Mesoscale and Nanoscale Physics · Physics 2024-05-21 E. V. Gorbar , V. P. Gusynin , D. O. Oriekhov , B. I. Shklovskii

In this Letter, we derive an effective theory of graphene on a hexagonal Boron Nitride (h-BN) substrate. We show that the h-BN substrate generically opens a spectral gap in graphene despite the lattice mismatch. The origin of that gap is…

Mesoscale and Nanoscale Physics · Physics 2012-11-12 M. Kindermann , Bruno Uchoa , D. L. Miller

Magic angle twisted bilayer graphene has emerged as a powerful platform for studying strongly correlated electron physics, owing to its almost dispersionless low-energy bands and the ability to tune the band filling by electrostatic gating.…

Mesoscale and Nanoscale Physics · Physics 2021-07-21 Nikhil Tilak , Xinyuan Lai , Shuang Wu , Zhenyuan Zhang , Mingyu Xu , Raquel de Almeida Ribeiro , Paul C Canfield , Eva Y. Andrei

We calculate the finite-frequency conductivity of bilayer graphene with a relative twist between the layers. The low frequency response at zero doping shows a flat conductivity with value twice that of the monolayer case and at higher…

Mesoscale and Nanoscale Physics · Physics 2013-03-12 Calvin J. Tabert , Elisabeth J. Nicol

The importance of controlling both the charge carrier density and the band gap of a semiconductor cannot be overstated, as it opens the doors to a wide range of applications, including, e.g., highly-tunable transistors, photodetectors, and…

We review the electronic properties of bilayer graphene, beginning with a description of the tight-binding model of bilayer graphene and the derivation of the effective Hamiltonian describing massive chiral quasiparticles in two parabolic…

Mesoscale and Nanoscale Physics · Physics 2013-04-23 Edward McCann , Mikito Koshino

We study, within the tight-binding approximation, the electronic properties of a graphene bilayer in the presence of an external electric field applied perpendicular to the system -- \emph{biased bilayer}. The effect of the perpendicular…

We investigate the transport properties of double-gated bilayer graphene nanoribbons at room temperature. The devices were fabricated using conventional CMOS-compatible processes. By analyzing the dependence of the resistance at the charge…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 Bartholomaeus N. Szafranek , Daniel Schall , Martin Otto , Daniel Neumaier , Heinrich Kurz

It has been predicted that application of a strong electric field perpendicular to the plane of bilayer graphene can induce a significant band gap. We have measured the optical conductivity of bilayer graphene with an efficient electrolyte…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Kin Fai Mak , Chun Hung Lui , Jie Shan , Tony F. Heinz

We calculate the optical sum associated with the in-plane conductivity of a graphene bilayer. A bilayer asymmetry gap generated in a field-effect device can split apart valence and conduction bands, which otherwise would meet at two K…

Mesoscale and Nanoscale Physics · Physics 2008-04-08 L. Benfatto , S. G. Sharapov , J. P. Carbotte

A transformation of the band structure in bilayer graphene (BLG) with relatively shifted layers has been studied in the framework of the tight-binding model. BLG is demonstrated to remain a zero-gap material in the whole range of…

Mesoscale and Nanoscale Physics · Physics 2014-01-07 V. G. Litovchenko , A. I. Kurchak , M. V. Strikha

We demonstrate that the low-frequency resistance fluctuations, or noise, in bilayer graphene is strongly connected to its band structure, and displays a minimum when the gap between the conduction and valence band is zero. Using…

Mesoscale and Nanoscale Physics · Physics 2010-06-09 Atindra Nath Pal , Arindam Ghosh

Bilayer graphene has drawn significant attention due to the opening of a band gap in its low energy electronic spectrum, which offers a promising route to electronic applications. The gap can be either tunable through an external electric…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Gregory M. Rutter , Suyong Jung , Nikolai N. Klimov , David B. Newell , Nikolai B. Zhitenev , Joseph A. Stroscio

We show simultaneous p and n type carrier injection in bilayer graphene channel by varying the longitudinal bias across the channel and the top gate voltage. The top gate is applied electrochemically using solid polymer electrolyte and the…

Mesoscale and Nanoscale Physics · Physics 2009-09-08 Biswanath Chakraborty , Anindya Das , A. K. Sood